(a) Field of the Invention
The present invention relates to an apparatus and method for transmitting and receiving data and, more particularly, to an apparatus and method for transmitting and receiving data using orthogonal frequency-division multiplexing (OFDM) modulation and angle modulation.
(b) Description of the Related Art
OFDM, which can be implemented through a simple equalizer and has characteristics resistant to multi-path fading, is employed in various wireless communication systems such as a wireless local area network (WLAN), a wireless metropolitan area network (WMAN), digital audio broadcast (DAB), digital video broadcast (DVB), and the like.
However, since OFDM uses multiple carriers, in-phase signals are joined (or mixed) to generate a high peak-to-average power ratio (PAPR), and an operating point of a power amplifier of an OFDM transmitter is positioned in a nonlinear area due to the high PAPR, causing nonlinear distortion of signals. Thus, in order to reduce the influence of PAPR, in an OFDM system, a power amplifier is backed off, and herein if sufficient backoff is not provided to the power amplifier, a frequency spectrum of the system is widened and distortion is generated by modulation between frequencies, resulting in degradation of performance of the system.